"I owe a great deal to Mr. Twitters, and I hope I shall discover a way to show my gratitude," said the Professor more than once, and he did, as you will see. It was a very happy winter, in spite of rain and snow, and as spring came on, the three friends had fine times in the park. Bertie fed his birds there now; and they, remembering how he had kept them alive through the bitter weather, seemed to love him more than ever. They flocked round him as soon as he appeared, chirping, fluttering, pecking, and hopping so fearlessly and gayly, that people often came to see the pretty sight, and "Bertie's birds" were one of the lions of the neighborhood. Cocky was very busy and important about this time. His tail-feathers had grown again, he seemed to have put on a new drab waistcoat, and his head was so sleek that Bertie was sure he used pomade. When he called at the balcony, he often brought another sparrow with him,--a plump, downy bird, with a bright eye, a Quakerish dress, and very gentle manners. "Mamma says Cocky is going to be married, and that pretty one is his little sweetheart. Won't it be nice? I wonder if he will ask us to the wedding, and where he will live!" said Bertie, standing still in the park, staring up at the nests stuck on the elm boughs, now green with tender leaves and noisy with happy birds. "I don't think he will ask us, and I very much fear that there won't be room in that brown nest for the old papa and the young folks also," answered Mr. P., staring as hard as Bertie did. "Then we must ask the mayor to have a new house put up for Cocky. Don't you think he would if I wrote him a nice letter and showed him your book? He'd see what a brave good bird my Twitters is, and give him a nice house, I'm sure," said Bertie earnestly, for he would believe that Cocky had really done all the fine and funny things recounted in that remarkable book. "Leave it to me, boy. I will see what can be done about a mansion for Cocky to begin housekeeping in;" and Mr. P. gave a knowing nod, as if he had a new idea. So Bertie said no more, and, soon after this conversation, went to Plymouth, on a visit with mamma. May-day was coming, and Bertie wanted to hang baskets on the doors of young and old neighbors; chief among the latter his dear Mr. P. Nowhere in New England do May-flowers grow so large and rosy, or bloom so early and so sweet as in Plymouth, and Bertie gathered a great hamper full of the best, made up in nosegays, garlands, and baskets. Then they came home, and all along the way people sniffed and peeped and smiled at the odorous load which the boy guarded so carefully and rejoiced over so much.